Portion of tractor



FIG. 1 is a front elevational view of a portion of tractor, showing our design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is an enlarged top and left front perspective view of the portion of tractor shown within an area defined by A-A′ and B-B′ in FIG. 3, the area being indicated by long dash short dash broken lines in FIG. 6;

FIG. 7 is an enlarged top and left rear perspective view of the portion of tractor shown within the area defined by A-A′ and B-B′ in FIG. 3, the area being indicated by long dash short dash broken lines in FIGS. 7; and,

FIG. 8 is an enlarged left side elevational view of the portion of tractor shown within an area defined by A-A′ and B-B′ in FIG. 3, the area being indicated by long dash short dash broken lines in FIG. 8.

All broken lines shown in the figures represent environmental structures and form no part of the claimed design. 

CLAIM The ornamental design for a portion of tractor, as shown and described. 